In an email to developers, HP said it never authorized the distribution of any version of Android on the TouchPad and that after a review of its manufacturing process, it believes no TouchPads were shipped by HP with Android, even by mistake. The developers reached out to HP because they believe that HP is obligated under open-source licensing terms to share the Android distribution that shipped on the TouchPads.

The email, signed by Phil Robb, director of HP's open-source program office, was posted on a developer discussion group online. HP confirmed that the email is accurate. "We believe that some person or persons unknown may have facilitated the delivery of these Android-based units strictly against the policy and authorization of HP," Robb wrote. He asked the developers for any information they could offer that would help HP track down who provided the Android TouchPads.

The developers also say they've emailed Qualcomm with a request to release the code since some versions of the Android tablets flash a QuIC logo. QuIC, or Qualcomm Innovation Center, is a Qualcomm engineering subsidiary that works on optimizing open-source software on Qualcomm products. But in an email the developers posted online, Qualcomm said the device was not manufactured or distributed by QuIC.

Qualcomm did not immediately reply to a request for comment.

HP's Robb declined to share the source code for running Android on the TouchPad but didn't appear to deny that it exists. "Regarding your specific request for source code below, I must decline at the present time. HP has never authorized the distribution of any binaries for Android in association with the HP TouchPad. Therefore, HP is not under any license obligation to provide any corresponding Android source code to you," he wrote.

The developers are continuing to try to track down where each of the Android TouchPads came from to try to determine where and by whom Android was loaded onto the tablets.